Question

An aquarium filled with water has flat glass sides whose index of
refraction is 1.52. A beam of light from outside the aquarium
strikes the glass at a ? = 42.0° angle to the perpendicular (Fig.
23-49).

(a) What is the angle of this light ray when it enters the
glass?
(b) What is the angle of this light ray when it then enters the
water?
(c) What would be the refracted angle if the ray entered the water
directly?